The iPhone Messages application which was introduced in iOS 5 makes it easy to communicate between iOS devices for free, while still talk to other phones using SMS and MMS.
The Messages app is the default iPhone SMS method, but it is not the only one or the only way.
The App Store is full of Text messaging applications that allow you to send and receive text messages from any one in the world for free, or at very low cost.
Applications like Google Voice, textPlus, WhatsApp, or Textie Messaging are all good alternatives to the default SMS service that comes with your iPhone carrier.
Some cable providers like Xfinity provide SMS for free if you have a phone service with them. Your home phone number will be linked to your iPhone but it will be the phone number to send and receive messages.
If you have a jailbroken iPhone, you can benefit from other tools that allow you to boost the power of your default iPhone SMS using an application like BiteSMS.
Once you apply some of the iPhone hacks described in this website, you will be able to send and receive free SMS messages, and MMS messages to anyone in the USA, or to anyone outside the USA for low international rates.
The Default iPhone Messages App:
The Messages app or iMessage was improved dramatically starting with iOS 5. It has its simplicity and clean appearance. But it still lacks many features that are available in high end SMS applications.
For example, you must open the Message application
every time you want to send a text message as shown below. There is no quick compose, or compose a text message from the lock screen.
iMessage for the iPhone allows you to send a picture or MMS message by tapping the camera icon and selecting an existing picture from your iPhone photo library or you can capture a picture using your iPhone camera and immediately send it.
If you have an iPhone 5 or iPhone 4S, you can use Siri to easily send a text message. You can simply speak your message to create it and send it.
To send a message using Siri, simply activate Siri by pressing and holding the home button. Your iPhone will beep twice indicating the Siri is listening. You can then say "send a test message", and follow what Siri asks you.
Or, you can create and send the whole message in one voice. Just say "send a message to "whoever" saying "whatever".
Google voice is a service provided by Google mostly for free if you live in the US and have a US phone number. There are many services available for Google Voice like linking several phone numbers to one phone number, and the ability to forward one phone number to another.
Google voice also allows you to send and receive SMS messages for free from and to anyone in the USA and Canada. Your family and friends from the US and Canada can also call you as a local phone call while you are outside of the US because you will have a local google voice phone number.
WhatsApp is one of the most popular free iPhone text messages applications in the App store and on other stores on Android, and Windows Phone. WhatsApp allows you to send and receive messages and other media files from any mobile phone as long as you have a phone number linked to your account. It is a universal app that cost $0.99 from the App store.
However, once you jailbreak your iPhone and have access to the Cydia store, biteSMS is the best way to use your iPhone to send and receive text messages either using your carrier plan, or using BiteSMS own plan at low cost.